Synthesis, characterization, and nonlinear optical properties of some new series of S-(5-aryl-1,3,4-oxadiazol-2-yl) 2-chloroethanethioate derivatives

In the present investigation, some novel S-(5-aryl-1,3,4-oxadiazol-2-yl)2-chloroethanethioate (3a-3e) derivatives were synthesized and their impact on optical properties was studied. They have also been characterized by elemental analysis and various spectroscopic methods including FTIR, $^{1}$H NMR, $^{13}$C NMR, and UV-Vis techniques. The nonlinear refractive indexes of 3a-3e were also measured in dichloromethane via Z-scan method using a continuous wave diode-pumped laser at 532 nm wavelength. The nonlinear refractive coefficient of compounds was obtained from ${10}^{11}\, \, {m}^{{2}}{/W}$ order. Regarding the appropriate nonlinearity of these compounds, they could be considered good candidates for biooptical and photonic applications. All the synthesized compounds (3a-3e) have also been evaluated for their antimicrobial and antifungal activities. The bioactive assay showed that the synthetic compounds displayed variable inhibition zones against tested bacterium Escherichia coli and fungus Aspergillus fumigatus in comparison to enrofloxacin and amphotericin as reference drugs, which are normally used for treating such infections.